Battosai in Pale Pastels

I've been majoring in graphic arts, print, for a few years now and I realized a while back that I need to really upgrade my illustrator skills. So, I've begun creating some fan art using Illustrator.

This Rurouni Kenshin piece gave me a real feel for how to work with curved lines using the pen tool. I'm getting better, but still a way to go, I think. Still, I like this piece quite a bit.

If anyone has a suggestions for improvement, etc., I'd love to hear them.